The present invention relates to a device for reducing the noise during a potentiometer evaluation. In particular, it relates to a device for reducing the noise during evaluation with a throttle flap potentiometer or an air mass measuring potentiometer, for example an air flow sensor flap of an internal combustion engine.
It is well known in the prior art that the position of the throttle flap, from which the quantity of the air aspirated by the internal combustion engine depends, is determined with the aid of a throttle flap potentiometer. The throttle flap potentiometer correspond to a mechanically variable resistance which is connected as a voltage divider and the signal voltage is taken at its slider output. Only relatively narrow tolerances are permitted for the electrical values due to the required accurate association of the voltage values and the potentiometer position. They also must be maintained over a long operational time. Because of aging, action of oil, fuel, condensation water, etc. the transfer resistance of the slider can be changed so that the undesired voltage breaks occur and lead to a noisy signal. As a result, the relationship of the signal voltage and the slider position can be erroneous which in turn can lead to undesirable travelling conditions.